Dogs are ubiquitous in society today: they are our best friends, cuddle buddies, and all-around furry play pals. They can be found everywhere, from back yards and family couches to the streets of major cities around the world. Dogs have come to symbolize loyalty and companionship, and have been the subjects of major works of art, novels, and movies. We have come to think of them as an established part of the human world, not as wild animals.

It might surprise many people to learn that, in fact, dogs share up to 99.96% of their DNA with the modern Grey Wolf. The nearly genetic match between dogs and wolves has even prompted some scientists to suggest that dogs are merely a sub-species of wolves, rather than a separate species unto themselves. Yes, even your tiny Chihuahua with its adorable underbite is nearly genetically identical to a mighty wolf!

So how did dogs diverge from wolves? When did humans domesticate them, and how in the world did we get the Chihuahua from a wolf??? Most scientists agree that dogs first began to diverge from wolves between 27,000 to 40,000 years ago. However, that is about where the agreement ends. Some studies suggest that dogs are related to one single group of domesticated wolves from Asia. Others suggest that there were many domestication events all around the globe, from Europe and Asia to the Americas. The truth, most scientists agree, is probably some combination of the two. What we do know is that in analyzing modern dog DNA, the difference between dogs and wolves is extremely slight.

And the Chihuahua? Well, that dog is just an amazing example of how humans can, over time and many generations, breed animals for extremely specific traits. If two small dogs breed with each other, they are likely to produce offspring that is also small. If those small offspring breed with other small dogs, their puppies will likely be even smaller. In choosing dogs to breed that had similar specific traits, humans were able to create the Chihuahua.

Activity: Reading Scientific Paper Abstracts

Reading scientific papers can be incredibly difficult for students. To help ease students in, begin by simply reading abstracts. The abstract contains the general hypothesis, findings, and conclusions of a paper, and is a great gateway into understanding the principles of science.

Choose an appropriate paper. Here is an excellent paper on the evolution of dogs.

Give students 10 minutes to read the abstract on their own. They should ID:

The intent or goal of the study.

The findings of the study.

Put students into small groups of 2-3 people each. Allow 5 minutes for groups to share their findings with each other.

Ask 2-3 groups to share with the whole class their findings from reading the abstract.

The students were active and engaged for the whole lesson. They were asked to talk, predict, and brainstorm with peers. They used creativity. The group management skills of the presenters was outstanding.